The while loop starts by evaluating the condition. If the condition is true, the statement(s) is/are executed. If the condition is false, the statement(s) is/are not executed. After that, while loop ends.

Here is the syntax for while loop:

while (condition)

{

  statement(s);

}

statement(s): A statement that is executed as long as the condition evaluates to true.

condition: Here, condition is a Boolean expression which is evaluated before each pass through the loop. If this condition evaluates to true, statement(s) is/are executed. When condition evaluates to false, execution continues with the statement after the while loop.

    var i = 1;
    while (i < 10) 
    {
      console.log(i);
       i++;
    }

    Output:
    1 
    2 
    3 
    4
    5
    6
    7
    8
    9

source:While Loop